Calculating cardiac output (Edexcel GCSE Biology & Combined Science)

This lesson describes the meaning of the terms stroke volume and heart rate and explains how to use them to calculate the cardiac output. The PowerPoint and accompanying resources have been designed to cover the content of specification point 8.12 of the Edexcel GCSE Biology & Combined Science specifications.

The lesson begins by challenging the students to use their knowledge of the structure of the heart chambers to identify the one which has the most muscular wall. Their discussions should lead to the left ventricle and following the introduction of the key term stroke volume using a quick quiz competition, they will learn that this factor is the volume of blood pumped out of the left ventricle each heart beat. Another competition introduces the normative values for stroke volume and the resting heart rate and then the students are challenged to use the provided equation to calculate the cardiac output and to write a definition for this factor using their current understanding. The remainder of the lesson considers how these three factors change during exercise and they are challenged to apply their understanding through a series of exam questions. This worksheet is differentiated two ways and the mark scheme is embedded into the PowerPoint to allow the students to assess their progress.